ON A ZOOLOGICAL SURVEY FROM AN ENTOMO- 

 LOGICAL POINT OF VIEW. 



By A. J. T. Janse, F.E.S. 



(Abstract.) 



Read July 9, 1919. 



Last year (1918) I tried to point out how rich the 

 insect fauna of South Africa is, how much work still remains 

 to be done, and how fast the flora, and with that the insect 

 fauna, is changing in our country owing to the ever-advancing 

 agriculture. This was done in order to convince you of the 

 necessity of having an organised zoological survey for South 

 Africa, supported by the Government and assisted by all students 

 of zoology in South Africa. 



In this paper I try to deal with the question from an 

 entomological point of view, though in some people's view the 

 study of insects is not quite as important as that of other classes 

 of animals. Entomological studies are often looked upon as 

 scientific luxuries, hardly necessities, unless, indeed, it is in 

 solving questions of economic importance. Still, I maintain 

 that it is hardly possible to draw a line of distinct demarcation 

 anywhere in science, and least of all in entomology. How im- 

 portant this group is may be realised by the fact that not less 

 than half the existing animals are insects. 



I, therefore, hold that in a proposed zoological survey the 

 study of insects should stand foremost from an economic and 

 scientific point of view. 



Such a survey would probably in the first place constitute 

 a proper collecting of material, and here more has to be done 

 than in any other group of animals. It is comparatively diffi- 

 cult to find new species in most other groups, but in practically 

 any order of insects the number of unknown species is probably 

 as large as those that have been descri])ed. 



Examples from an order with which I am best acquainted 

 may illustrate this. Of the South African Heterocera (moths) 

 4,025 species have been described up to now, 2,400 named species 

 of which are now in my collection, but not less than about 2,000 

 unnamed species are in that collection as well, and fresh species 

 are discovered about every week. (Nearly 900 of these un- 

 named species were shown at the meeting, only 20 of which, 

 as was proved later, were represented in the South African 

 Museum.) 



